Method for producing a crystalline polyester resin composition and method for producing a molded article

Abstract

The present invention provides a novel method for producing a crystalline polyester resin composition that allows for the provision of crystalline polyester resins at low cost and in a state where adhesion between the polyester resins is prevented or reduced. [Solution] A mixing step of mixing a polyester resin (A) and an anti-sticking agent (B), A method for producing a crystalline polyester resin composition, comprising a heating step of heating the mixture obtained in the mixing step to 115°C or higher.

Description

Technical Field

[0001] The present invention relates to a method for producing a crystallized polyester resin composition and a method for producing a molded article.

Background Art

[0002] Thermoplastic polyester resins such as polyethylene terephthalate are excellent in transparency, mechanical properties, gas barrier properties, heat resistance, solvent resistance, economy, recyclability, etc. Therefore, polyester resins are applied to various molding applications such as bottles.

[0003] In recent years, from the viewpoints of resource reuse and global environmental protection, attention has been focused on technologies for collecting waste polyester resins that have been used once and recycling them as recycled polyester resins.

[0004] For example, Patent Document 1 discloses a resin composition containing a polyester resin recycled from a polyester resin molded article and a resin other than polyester, and a molded article thereof.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Before using polyester resins as molding materials, a crystalline polyester resin composition is sometimes required, which is obtained by crystallizing the polyester resin. Conventionally, in the production of crystalline polyester resin compositions, it was necessary to heat and stir the polyester resin to crystallize it in order to prevent the uncrystallized polyester resins from sticking together, and for this purpose, expensive crystallization equipment was used. However, conventional methods using expensive crystallization equipment had the problem of increasing costs.

[0007] One embodiment of the present invention has been made in view of the above-mentioned problems, and its object is to provide a novel method for producing a crystalline polyester resin composition that can provide a crystalline polyester resin at low cost and in a state in which adhesion between the polyester resins is prevented or reduced. [Means for solving the problem]

[0008] The present inventors have diligently studied to solve the aforementioned problems and have completed the present invention. Specifically, a method for producing a crystalline polyester resin composition according to one embodiment of the present invention comprises a mixing step of mixing a polyester resin (A) and an anti-adhesion agent (B), and a heating step of heating the mixture obtained in the mixing step at 115°C or higher. [Effects of the Invention]

[0009] According to one embodiment of the present invention, a crystalline polyester resin can be provided at a low cost, and in a state in which adhesion between the polyester resins is prevented or reduced. [Modes for carrying out the invention]

[0010] One embodiment of the present invention is described below, but the present invention is not limited thereto. The present invention is not limited to the configurations described below, and various modifications are possible within the scope of the claims. Furthermore, embodiments or examples obtained by combining the technical means disclosed in different embodiments or examples are also included in the technical scope of the present invention. Moreover, new technical features can be formed by combining the technical means disclosed in each embodiment. All academic and patent documents mentioned herein are incorporated herein by reference.

[0011] Unless otherwise specified in this specification, constituent units contained in polymers, copolymers, or resins are referred to as "constituent units derived from X monomers," "constituent units derived from X compounds," or "constituent units derived from X acids" as "X units."

[0012] In this specification, the "X monomer" may also be simply referred to as "X".

[0013] [1. Technical Concept of One Embodiment of an Embodiment] Generally, the molding material used is amorphous polyethylene terephthalate (A-PET) resin pellets obtained by rapidly cooling raw material resins with water after extrusion, and recycled polyester resin pellets obtained by crushing PET bottles, etc. The polyester resins used as raw materials for the molding application, such as the A-PET resin and the recycled polyester resin, are usually in an uncrystallized state. In addition, in order to be used for the molding application, the polyester resin that is the molding material usually needs to be dried at a temperature of 80°C or higher before molding. For example, in a molding method using the A-PET resin as the polyester resin, the A-PET resin is preferably dried at a temperature of 130°C or higher before molding.

[0014] It is known that when uncrystallized polyester resin is dried, the surface softens at temperatures between 70°C and 80°C, causing the resins to adhere to each other and form a lumpy mass. This lumpy polyester resin is unsuitable as a molding material. Therefore, in order to prevent or reduce this adhesion and obtain a polyester resin suitable as a molding material, conventional molding methods involved heating the uncrystallized polyester resin to crystallize it, and then drying the crystallized polyester resin. The dried, crystallized polyester resin was then molded. In other words, conventional molding methods included a method for producing a crystallized polyester resin composition.

[0015] In conventional methods for producing crystallized polyester resin compositions, a polyester resin composition containing an amorphous polyester resin was heated to crystallize the amorphous polyester resin. Typically, this crystallization required heating at a temperature of 115°C or higher. Therefore, as mentioned above, during crystallization, the surface of the polyester resin softened, causing the crystallized polyester resins to adhere to each other. As a result, a crystallized polyester resin composition in the form of a lumpy mass, unsuitable as a molding raw material, was sometimes obtained.

[0016] Therefore, as a method to prevent or reduce the aforementioned adhesion, conventionally, as described above, a method has been employed in which polyester resins are heated and crystallized using an expensive crystallization apparatus while being stirred.

[0017] On the other hand, the inventors diligently researched methods to prevent the adhesion of the polyester resin by a method other than the method of preventing or reducing the adhesion by crystallizing the polyester resin while stirring, which requires the expensive crystallization equipment.

[0018] As a result, the inventors have found that a polyester resin composition containing the polyester resin and a specific substance can be crystallized by heating using a general heating device such as a dryer, without requiring the expensive crystallization equipment, thereby preventing or reducing the adhesion. They have also found that the specific substance does not melt or adhere to each other even under the heating conditions during crystallization. From these findings, the inventors have hypothesized that the surface of the polyester resin containing the specific substance is coated with a substance that does not adhere to each other even under the heating conditions during crystallization. Furthermore, they hypothesize that this prevents or reduces contact between the softened surfaces of the polyester resin under the heating conditions during crystallization, thereby preventing or reducing the adhesion, and thus arrived at the present invention. It should be noted that one embodiment of the present invention is not limited in any way to this hypothesis.

[0019] [2. Method for producing crystalline polyester resin composition] A method for producing a crystalline polyester resin composition according to one embodiment of the present invention comprises a mixing step of mixing a polyester resin (A) and an anti-adhesion agent (B), and a heating step of heating the mixture obtained in the mixing step at 115°C or higher.

[0020] In this specification, "a method for producing a crystalline polyester resin composition according to one embodiment of the present invention" may be referred to as "this manufacturing method."

[0021] In the mixing step of this manufacturing method, a mixture containing a polyester resin (A) and an anti-adhesion agent (B) can be obtained. This mixture is also a composition containing the polyester resin (A) and the anti-adhesion agent (B). Therefore, in this specification, the "mixture containing the polyester resin (A) and the anti-adhesion agent (B)" may also be referred to as the "polyester resin composition" or "resin composition."

[0022] Since the polyester resin composition contains a polyester resin (A) and an anti - sticking agent (B), it is considered that at least a part of the surface of the polyester resin (A) is coated with the anti - sticking agent (B). In this specification, the "anti - sticking agent (B)" means an agent composed of substances that do not melt and do not stick to each other in the subsequent heating process. Further, in the heating process, the polyester resin (A) is heated and crystallized to produce a crystallized polyester resin composition.

[0023] Here, the crystallized polyester resins (A) with softened surfaces obtained as a result of the heating process are prevented or reduced from direct contact by the coating made of the anti - sticking agent (B). Also, the coating made of the anti - sticking agent (B) on the surface of one polyester resin (A) can come into contact with the coating made of the anti - sticking agent (B) on the surface of another polyester resin (A). However, since the anti - sticking agent (B) is composed of substances that do not stick to each other even under the heating conditions of the heating process, the coatings also do not stick to each other even when they come into contact in the heating process. Therefore, in this manufacturing method, a crystallized polyester resin is provided in a state where sticking between the crystallized polyester resins is prevented or reduced.

[0024] In addition, according to this manufacturing method, in order to prevent or reduce the sticking, it is not necessary to heat and crystallize the polyester resin (A) while stirring. Therefore, it is not necessary to use the expensive crystallization device for the stirring, and the crystallization can be carried out using an ordinary heating device such as a dryer. Therefore, according to this manufacturing method, a crystallized polyester resin can be provided at a low cost.

[0025] As described above, according to this manufacturing method, a crystallized polyester resin can be provided at a low cost and in a state where sticking between the polyester resins is prevented or reduced.

[0026] Below, we will first explain the raw materials (polyester resin (A) and anti-adhesion agent (B), etc.), and then describe the specific manufacturing process.

[0027] (Polyester resin (A)) The polyester resin (A) includes at least an uncrystalline polyester resin. This manufacturing method is a method for producing a crystalline polyester resin composition by crystallizing the uncrystalline polyester resin in the heating step. The uncrystalline polyester resin may be a crystalline polyester resin.

[0028] In this specification, "crystalline polyester resin" refers to a thermoplastic polyester resin in which, when the temperature of a molten polyester resin is lowered to a non-molten state, crystalline portions in which polymer molecules are regularly aligned can be formed within the resin.

[0029] The crystalline nature of polyester resins can usually be confirmed by the presence of a distinct endothermic peak in differential scanning calorimetry (DSC). Specifically, a distinct endothermic peak refers to an endothermic peak in the DSC curve obtained by differential scanning calorimetry (DSC) performed at a heating rate of 10°C / min, where the full width at half maximum (FMAX) is, for example, within 15°.

[0030] In one embodiment of the present invention, the polyester resin (A) may include an amorphous polyester resin. In one embodiment of the present invention, the polyester resin (A) may consist only of a crystalline polyester resin, or it may consist of a mixture of a crystalline polyester resin and an amorphous polyester resin. When the polyester resin (A) includes an amorphous polyester resin, the crystalline polyester resin composition obtained by this manufacturing method has the advantage of being a resin composition with a reduced degree of crystallization, which is optimal for injection blow molding.

[0031] In this specification, "amorphous polyester resin" refers to a highly transparent polyester resin that substantially lacks a crystalline structure.

[0032] The amorphous nature of polyester resins can usually be confirmed by the absence of a distinct endothermic peak in differential scanning calorimetry (DSC). A distinct endothermic peak is, specifically, an endothermic peak in the DSC curve obtained by differential scanning calorimetry (DSC) performed at a heating rate of 10°C / min, where the full width at half maximum (FMAX) is, for example, 15° or less.

[0033] In this specification, "crystallized polyester resin composition" refers to a composition containing a polyester resin in a crystallized crystalline state, i.e., a crystalline polyester resin. A polyester resin in a crystallized crystalline state may be a crystalline polyester resin.

[0034] In one embodiment of the present invention, the polyester resin (A) can be a known polyester resin and is not particularly limited. The polyester resin (A) may be a single resin or a mixture of two or more resins.

[0035] From the viewpoint of making it easier to form the crystalline polyester resin composition obtained by this manufacturing method into pellets useful for molding such as injection molding, extrusion molding, and blow molding, it is preferable that the shape of the polyester resin (A) is also pellet-like.

[0036] The polyester resin (A) may be an aromatic polyester having a structure in which an aromatic dicarboxylic acid or its ester derivative component and a diol component such as an aliphatic diol or alicyclic diol are linked by an ester reaction. The polyester resin (A) may also be obtained by polycondensation of an aromatic dicarboxylic acid or its ester derivative component and a diol component such as an aliphatic diol or alicyclic diol by a known method.

[0037] The aromatic dicarboxylic acid is not particularly limited, but examples include terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,2'-biphenyldicarboxylic acid, 3,3'-biphenyldicarboxylic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, 4,4'-diphenylmethanedicarboxylic acid, 4,4'-diphenylsulfonedicarboxylic acid, 4,4'-diphenylisopropylidenedicarboxylic acid, 1,2-bis(phenoxy)ethane-4,4'-dicarboxylic acid, 2,5-anthracenedicarboxylic acid, 2,6-anthracenedicarboxylic acid, 4,4'-p-terphenylenedicarboxylic acid, and 2,5-pyridinedicarboxylic acid. The aromatic dicarboxylic acid may be used alone or in combination of two or more types.

[0038] The aliphatic diol is not particularly limited, but examples include ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 2-methyl-1,3-propanediol, diethylene glycol, and triethylene glycol. The alicyclic diol is not particularly limited, but examples include 1,4-cyclohexanedimethanol. Only one type of diol component may be used, or two or more types may be used in combination.

[0039] The polyester resin (A) may have structural components derived from trifunctional or higher monomers such as glycerin, trimethylolpropane, pentaerythritol, trimellitic acid, and pyromellitic acid. Only one type of trifunctional or higher monomer may be used, or two or more types may be used in combination.

[0040] The polyester resin (A) mentioned above is not particularly limited, but examples include polyethylene terephthalate (PET), polypropylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, polybutylene naphthalate, poly-1,4-cyclohexylenedimethylene terephthalate, polyethylene-1,2-bis(phenoxy)ethane-4,4'-dicarboxylate, polyethylene isophthalate / terephthalate, polybutylene terephthalate / isophthalate, polybutylene terephthalate / decanedicarboxylate, polycyclohexanedimethylene terephthalate / isophthalate, polyester / polyether, and the like.

[0041] From the viewpoint of moldability and mechanical properties, the polyester resin (A) preferably contains (i) one or more selected from the group consisting of polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, polybutylene naphthalate, poly-1,4-cyclohexylenemethylene terephthalate, and polyester / polyether, and may consist only of one or more selected from the group; and (ii) more preferably contains one or more selected from the group consisting of polyethylene terephthalate and polybutylene terephthalate, and may consist only of one or more selected from the group.

[0042] The polyester resin (A) may contain recycled polyester resin, or may consist solely of recycled polyester resin.

[0043] In this specification, "recycled polyester resin" refers to polyester resins and / or polyester resin compositions obtained by recycling the following (Ai) and / or (Aii): (Ai) Polyester resin, polyester resin composition, and / or polyester resin molded articles that have been used and / or discarded after being commercialized as polyester resin, polyester resin composition, and / or polyester resin molded articles; (Aii) Disposable polyester resin, disposable polyester resin composition, and / or disposable polyester resin molded articles discharged during the manufacturing process of polyester resins, polyester resin compositions, and / or polyester resin molded articles.

[0044] The aforementioned recycling method can be any known recycling method, and is not particularly limited; for example, material recycling can be used.

[0045] When the polyester resin (A) includes recycled polyester resin, the embodiment of the present invention can significantly reduce the amount of plastic waste generated and the amount of plastic used in its manufacture. As a result, the embodiment of the present invention can contribute to achieving Sustainable Development Goals (SDGs), such as Goal 12, "Ensure sustainable consumption and production patterns."

[0046] In this specification, polyester resins that have never been commercialized may be referred to as "virgin polyester resins." In this specification, "recycled polyester resins" also include mixtures obtained by mixing "virgin polyester resins" with recycled polyester resins.

[0047] If the polyester resin (A) includes an amorphous polyester resin, it is particularly preferable that the amorphous polyester resin includes glycol-modified polyethylene terephthalate, and even more preferable that it consists solely of glycol-modified polyethylene terephthalate. "Glycol-modified polyethylene terephthalate" refers to a copolymer of terephthalic acid, ethylene glycol, and a glycol component other than ethylene glycol.

[0048] If the polyester resin (A) includes an amorphous polyester resin, the content of the amorphous polyester resin is preferably 5% by weight or more and 60% by weight or less, based on 100% by weight of the total weight of the polyester resin (A).

[0049] When the content of the amorphous polyester resin is 5% by weight or more relative to 100% by weight of the total polyester resin (A), the crystallized polyester resin composition obtained by this manufacturing method has the advantage of being a resin composition with a reduced degree of crystallization, which is optimal for injection molding, extrusion molding, and blow molding such as direct blow molding and injection blow molding. From this viewpoint, the lower limit of the content of the amorphous polyester resin is more preferably 8% by weight or more, more preferably 10% by weight or more, even more preferably 13% by weight or more, and particularly preferably 15% by weight or more, relative to 100% by weight of the total polyester resin (A).

[0050] When the content of the amorphous polyester resin is 60% by weight or less relative to 100% by weight of the total polyester resin (A), the crystalline polyester resin composition obtained by this manufacturing method has the advantage that physical properties derived from the crystalline polyester resin (e.g., chemical resistance and abrasion resistance) are fully exhibited. From this viewpoint, the upper limit of the content of the amorphous polyester resin is more preferably 50% by weight or less, more preferably 40% by weight or less, even more preferably 30% by weight or less, and particularly preferably 25% by weight or less, relative to 100% by weight of the total polyester resin (A).

[0051] <Anti-sticking agent (B)> In one embodiment of the present invention, the anti-adhesion agent (B) is a substance that does not melt or adhere to each other during the heating process, and is intended to have the property of preventing the polyester resins (A) from adhering to each other. The anti-adhesion agent (B) is not particularly limited as long as it has the above property.

[0052] From the viewpoint of preventing melting during heating and crystallization, and preventing the polyester resin (A) from sticking together, the anti-adhesion agent (B) preferably contains an inorganic substance, and more preferably is an inorganic substance, that is, composed solely of inorganic substances.

[0053] The inorganic substance is not particularly limited, but from the viewpoint of maintaining surface properties, it is preferable to include one or more selected from the group consisting of talc, light calcium carbonate, heavy calcium carbonate, mica, clay, silica, hydrotalcite, aluminum hydroxide, magnesium hydroxide, antimony oxide, titanium oxide, and glass powder, and it is more preferable that it consists only of one or more inorganic substances selected from the group.

[0054] In one embodiment of the present invention, if the amount of the anti-adhesion agent (B) used is greater than or equal to a predetermined amount, the surface of the polyester resin (A) can be sufficiently coated with the anti-adhesion agent (B) during the mixing step. As a result, the adhesion between the polyester resins (A) can be more effectively prevented or reduced in the crystalline polyester resin composition obtained by this manufacturing method. From this viewpoint, the amount of the anti-adhesion agent (B) used is preferably 0.05 parts by weight or more, more preferably 0.07 parts by weight or more, and even more preferably 0.10 parts by weight or more, based on 100 parts by weight of the total weight of the polyester resin (A).

[0055] On the other hand, controlling the amount of the anti-adhesion agent (B) used to a predetermined amount or less is preferable from the viewpoint of preventing costs from increasing unnecessarily and providing the crystallized polyester resin composition at a lower cost. From this viewpoint, the amount of the anti-adhesion agent (B) used is preferably 1.00 part by weight or less, more preferably 0.80 parts by weight or less, even more preferably 0.30 parts by weight or less, and most preferably 0.25 parts by weight or less, based on 100 parts by weight of the total weight of the polyester resin (A).

[0056] <Liquid> In one embodiment of the present invention, the method may further include a liquid substance application step, in which a liquid substance is applied to at least a portion of the surface of the polyester resin (A) before the mixing step. In the liquid substance application step, a polyester resin (A) with the liquid substance applied to at least a portion of its surface is obtained. Therefore, when the manufacturing method further includes the liquid substance application step, the polyester resin (A) with the liquid substance applied to at least a portion of its surface is subjected to the mixing step. As a result, in the mixing step, the polyester resin (A) and the anti-adhesion agent (B) adhere more firmly via the liquid substance. Therefore, in that case, in the mixing step, the surface of the polyester resin (A) is more preferably coated with the anti-adhesion agent (B), and as a result, the adhesion can be more preferably prevented.

[0057] In one embodiment of the present invention, the liquid is a liquid substance that does not impair the functions of the polyester resin (A) and the anti-adhesion agent (B), and is not particularly limited. The liquid is not particularly limited, but from the viewpoint of fixing the anti-adhesion agent (B) with the polyester resin (A), it is preferable that it contains one or more selected from the group consisting of liquid paraffin, process oil, epoxidized vegetable oil, acrylic oligomer, and plasticizer, and it is more preferable that it consists only of one or more substances selected from this group.

[0058] In one embodiment of the present invention, it is preferable that the amount of the liquid used is equal to or greater than a predetermined amount, from the viewpoint of more effectively preventing the aforementioned adhesion. From this viewpoint, the lower limit of the amount of the liquid used is preferably 0.0005 parts by weight or more, more preferably 0.0008 parts by weight or more, and even more preferably 0.0010 parts by weight or more, per 100 parts by weight of the polyester resin (A). On the other hand, if an excessive amount of the liquid is used, there is a risk that the anti-adhesion agent (B) present on the surface of the polyester resin (A) will be removed by the liquid. It is preferable that the amount of the liquid used is equal to or less than a predetermined amount, from the viewpoint of avoiding this and more effectively coating the surface of the polyester resin (A) with the anti-adhesion agent (B) in the mixing step, thereby more effectively preventing or reducing the adhesion. From this viewpoint, specifically, the upper limit of the amount of liquid used is preferably 0.5000 parts by weight or less, more preferably 0.0500 parts by weight or less, even more preferably 0.0300 parts by weight or less, even more preferably 0.0100 parts by weight or less, and particularly preferably 0.0050 parts by weight or less, based on 100 parts by weight of the polyester resin (A) used.

[0059] <Modifier (C)> In this manufacturing method, a modifier (C) may be used further. If a modifier (C) is used further in this manufacturing method, the mixing step may be a step of mixing a resin composition containing a polyester resin (A) and a modifier (C) with an anti-adhesion agent (B). Alternatively, the mixing step may be a step of mixing a polyester resin (A), an anti-adhesion agent (B), and a modifier (C). If the mixing step is a step of mixing a resin composition containing a polyester resin (A) and a modifier (C) with an anti-adhesion agent (B), the mixing step may include the following steps (a) and (b). Step (a): A step of mixing and / or melt-kneading a polyester resin (A) and a modifier (C) to obtain a resin composition containing the polyester resin (A) and the modifier (C), for example in particulate or pellet form. Step (b): A step of mixing the resin composition obtained in step (a), for example in particulate or pellet form, with the anti-adhesion agent (B) to obtain a mixture.

[0060] The present invention will now describe a manufacturing method in which a modifier (C) is further used (for example, the mixing step includes steps (a) and (b) above) and the liquid substance attachment step is also included. In this case, the liquid substance attachment step may be a step of attaching a liquid substance to at least a portion of the surface of the resin composition obtained in step (a), for example, in particulate or pellet form. When a liquid substance is attached to at least a portion of the surface of the resin composition, the liquid substance will naturally be attached to at least a portion of the surface of the polyester resin (A). In this case, step (b) is more specifically the following step (b'). Step (b'): A step of mixing the resin composition and the anti-adhesion agent (B), which have a liquid substance attached to at least a portion of their surface, for example, in particulate or pellet form, to obtain a mixture.

[0061] In this specification, "modifier" means "an agent that can change the physical properties of a polyester resin (for example, improve melt viscosity)." The modifier (C) comprises a polymer (C1) containing reactive functional group-containing units and reactive functional group-free units. With this configuration, the modifier (C) can change the physical properties of the polyester resin (A) (for example, improve melt viscosity).

[0062] Polyester resins can deteriorate with each processing step (e.g., melt mixing), for example, due to heat, which can shorten the molecular chains of the resin and reduce its physical properties. The physical properties of recycled polyester resins obtained by recycling polyester resin products, such as melt viscosity, may be inferior (lower) compared to the physical properties of the polyester resin used as the raw material for those products, such as melt viscosity.

[0063] If the modifier (C) is further mixed in the mixing step, it has the advantage of improving the physical properties of the polyester resin (A), such as its melt viscosity. If the polyester resin (A) includes recycled polyester resin, it is highly significant to further mix in the modifier (C) in the mixing step, as this modifier can improve the physical properties (such as its melt viscosity) of the recycled polyester resin.

[0064] (C1 polymer) Polymer (C1) includes units containing reactive functional groups and units not containing reactive functional groups.

[0065] (Units containing reactive functional groups) In this specification, "reactive functional group" means a functional group that can react with the terminal functional groups of the polyester resin (A). In this specification, "reactive functional group-containing unit" means a constituent unit having a reactive functional group, and is a constituent unit derived from a monomer having a reactive functional group (hereinafter sometimes referred to as "reactive functional group-containing monomer").

[0066] In the mixing step, the reactive functional group (e.g., epoxy group) of the reactive functional group-containing unit in the polymer (C1) contained in the modifier (C) may react with the terminal functional group (e.g., hydroxyl group or carboxyl group) of the polyester resin (A), and such reaction may elongate the molecular chain of the polyester resin (A). In other words, the polymer (C1) contained in the modifier (C) may have the function of elongating the molecular chain of the polyester resin (A), or to put it another way, the polymer (C1) contained in the modifier (C) may function as a chain extender (or viscosity modifier) ​​for the polyester resin (A). Furthermore, by including the polymer (C1) described above in the modifier (C), the modifier (C) and the polyester resin (A) may be mixed more uniformly in the mixing step, that is, the dispersibility of the modifier (C) may be improved. As a result of improving the dispersibility of the modifier (C) and extending the molecular chains of the polyester resin (A), the melt viscosity (IV value) of the polyester resin (A) can be improved, and a resin composition with a higher melt viscosity than the polyester resin (A) can be obtained. However, the present invention is not limited in any way to these assumptions.

[0067] As described above, in the mixing step, the reactive functional groups (e.g., epoxy groups) of the reactive functional group-containing units in the polymer (C1) contained in the modifier (C) may react with the terminal functional groups (e.g., hydroxyl groups or carboxyl groups) of the polyester resin (A). Therefore, in the modifier (C) before mixing with the polyester resin (A) in the mixing step, the reactive functional group-containing units exist in a state where they are reacting with the terminal functional groups of the polyester resin (A). On the other hand, in the resin composition obtained in the mixing step, as a result of the reaction between the modifier (C) and the polyester resin (A), at least a portion of the modifier (C) may exist as constituent units derived from the modifier (C). Therefore, in the constituent units derived from the modifier (C) in the resin composition obtained in the mixing step, at least a portion of the reactive functional group-containing units may exist in a state where they are covalently bonded to the terminals of the polyester resin (A) units in the resin composition.

[0068] The reactive functional group is not particularly limited as long as it is a functional group that can react with the terminal functional groups of the polyester resin (A), and may be, for example, at least one functional group selected from the group consisting of epoxy groups, oxetane groups, hydroxyl groups, amino group-containing monomers, imide groups, carboxylic acid groups, and carboxylic acid anhydride groups.

[0069] The reactive functional group-containing units may be constituent units derived from cyclic ester-containing monomers and constituent units derived from cyclic amide-containing monomers.

[0070] In this specification, a "reactive functional group-containing monomer having an X group as a reactive functional group" may be referred to as an "X group-containing monomer," and a "constituent unit derived from a reactive functional group-containing monomer having an X group as a reactive functional group," i.e., a "constituent unit having an X group as a reactive functional group," may be referred to as an "X group-containing unit." Furthermore, in this specification, a "reactive functional group-containing monomer having an X group as a reactive functional group" may be referred to as a "Y monomer having an X group" or an "X group-containing Y monomer." Furthermore, in this specification, "constituent units derived from a Y monomer having an X group" and "constituent units derived from an X group-containing Y monomer" may be collectively referred to as an "X group-containing Y unit."

[0071] Specific examples of epoxy group-containing monomers include glycidyl group-containing vinyl monomers such as glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, 3,4-epoxycyclohexyl (meth)acrylate, allyl glycidyl ether, β-methylglycidyl (meth)acrylate, and 4-vinylbenzyl glycidyl ether. Glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, 3,4-epoxycyclohexyl (meth)acrylate, and β-methylglycidyl (meth)acrylate can also be called epoxy group-containing (meth)acrylates. Among these, from the viewpoint of reactivity, epoxy group-containing (meth)acrylates are preferred as epoxy group-containing monomers, glycidyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate glycidyl ether are more preferred, glycidyl methacrylate and 4-hydroxybutyl acrylate glycidyl ether are even more preferred, and glycidyl methacrylate is even more preferred. In this specification, "(meth)acrylate" means "acrylate and / or methacrylate". The epoxy group-containing monomer may be one type of epoxy group-containing monomer or a combination of two or more types of epoxy group-containing monomers.

[0072] Specific examples of oxetane group-containing monomers include, for example, (vinyloxyalkyl)alkyloxetane, (meth)acryloyloxyalkyloxetane, and [(meth)acryloyloxyalkyl]alkyloxetane. In this specification, "(meth)acryloyl" means "acryloyl and / or methacryloyl." The oxetane group-containing monomer may be one type of oxetane group-containing monomer, or a combination of two or more types of oxetane group-containing monomers.

[0073] Specific examples of hydroxyl group-containing monomers include, for example, (a) hydroxylinear alkyl(meth)acrylates such as 2-hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, and 4-hydroxybutyl(meth)acrylate (particularly preferred are hydroxylinear C1-6 alkyl(meth)acrylates); (b) caprolactone-modified hydroxy(meth)acrylates; (c) hydroxybranched alkyl(meth)acrylates such as methyl α-(hydroxymethyl)(meth)acrylate and ethyl α-(hydroxymethyl)(meth)acrylate; (d) hydroxyl group-containing (meth)acrylates such as mono(meth)acrylates of polyester diols obtained from divalent carboxylic acids (such as phthalic acid) and divalent alcohols (such as propylene glycol) (particularly preferred are saturated polyester diols); and (e) hydroxyl group-containing maleates. Note that "linear C1-6 alkyl" refers to linear alkyls having 1 to 6 carbon atoms. In this specification, "(meth)acrylic acid" means "acrylic acid and / or methacrylic acid." The hydroxyl group-containing monomer may be one type of hydroxyl group-containing monomer or a combination of two or more types of hydroxyl group-containing monomers.

[0074] Specific examples of amino group-containing monomers include, for example, N,N-dimethylaminoethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, N,N-dimethylaminopropyl (meth)acrylate, N,N-diethylaminopropyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylamide, N,N-diethylaminoethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N,N-diethylaminopropyl (meth)acrylamide, 2-vinylpyridine, 4-vinylpyridine, and these H + X - Examples include compounds having a structure obtained by neutralization with an acid represented by . The amino group-containing monomer may be one type of amino group-containing monomer, or a combination of two or more types of amino group-containing monomers.

[0075] Specific examples of imide group-containing monomers include maleimide, phenylmaleimide, N-methylmaleimide, N-ethylmaleimide, N-propylmaleimide, N-isopropylmaleimide, N-butylmaleimide, N-isobutylmaleimide, Nt-butylmaleimide, N-cyclohexylmaleimide, N-chlorophenylmaleimide, N-methylphenylmaleimide, N-bromophenylmaleimide, N-naphthylmaleimide, N-laurylmaleimide, N-hydroxyphenylmaleimide, N-methoxyphenylmaleimide, N-carboxyphenylmaleimide, N-nitrophenylmaleimide, and N-benzylmaleimide. The imide group-containing monomer may be a single type of imide group-containing monomer, or a combination of two or more types of imide group-containing monomers.

[0076] Specific examples of carboxylic acid group-containing monomers include monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, as well as dicarboxylic acids such as maleic acid, fumaric acid, and itaconic acid. From the viewpoint of reactivity, monocarboxylic acids are preferred as the carboxylic acid group-containing monomer. The carboxylic acid group-containing monomer may be one type of carboxylic acid group-containing monomer, or a combination of two or more types of carboxylic acid group-containing monomers.

[0077] Specific examples of monomers containing carboxylic acid anhydride groups include, for example, maleic anhydride. The monomer containing carboxylic acid anhydride groups may be one type of monomer containing carboxylic acid anhydride groups, or a combination of two or more types of monomers containing carboxylic acid anhydride groups.

[0078] The reactive functional group-containing units in polymer (C1) may consist of (i) only one type of reactive functional group-containing unit derived from any one of the reactive functional group-containing monomers mentioned above, or (ii) any combination of two or more reactive functional group-containing units derived from any two or more reactive functional group-containing monomers mentioned above.

[0079] From the viewpoint of obtaining a polyester resin composition with improved melt viscosity (IV value) through the reaction of the polyester resin (A) and the modifier (C), the reactive functional group-containing units in the polymer (C1) preferably include one or more selected from the group consisting of epoxy group-containing units, hydroxyl group-containing units, carboxylic acid group-containing units, and carboxylic acid anhydride group-containing units, and may consist only of one or more selected from the group; and (ii) epoxy group-containing (meth)acrylate units, hydroxyl group-containing maleate units, monocarboxylic acid units, dicarboxylic acid units, and carboxylic acid anhydride units. It is even more preferable to include one or more selected from the group consisting of physical group-containing units, and it may consist only of one or more selected from said group; (iii) It is even more preferable to include one or more selected from the group consisting of epoxy group-containing (meth)acrylate units, hydroxyl group-containing maleate units, acrylic acid units, methacrylic acid units, maleic acid units, and maleic anhydride units, and it may consist only of one or more selected from said group; (iv) It is particularly preferable to include epoxy group-containing (meth)acrylate units, and it may consist only of epoxy group-containing (meth)acrylate units.

[0080] From the viewpoint of polymerization productivity of reactive functional group-containing monomers from which reactive functional group-containing units are derived, the reactive functional group-containing units in polymer (C1) preferably contain one or more selected from the group consisting of (i) glycidyl (meth)acrylate units, 4-hydroxybutyl (meth)acrylate glycidyl ether units, 3,4-epoxycyclohexyl (meth)acrylate units and β-methylglycidyl (meth)acrylate units, and may consist only of one or more selected from the group, and (ii) glycidyl (meth)acrylate units, 4-hydroxybutyl acrylate glycidyl (iii) It is more preferable to include one or more selected from the group consisting of ether units and 3,4-epoxycyclohexyl (meth)acrylate units, and it may consist of only one or more selected from said group; (iv) It is most preferable to include glycidyl (meth)acrylate units and 4-hydroxybutyl acrylate glycidyl ether units, and it may consist of only one or more selected from said group; (iv) It is most preferable to include glycidyl methacrylate units, and it may consist of only glycidyl methacrylate units.

[0081] The content of reactive functional group-containing units in polymer (C1) is not particularly limited, but is preferably 5% by weight or more and 60% by weight or less per 100% by weight of polymer (C1). The upper limit of the content may be 55% by weight or less, 50% by weight or less, 45% by weight or less, or 40% by weight or less, and the lower limit may be 7% by weight or more, 10% by weight or more, 15% by weight or more, 20% by weight or more, 25% by weight or more, or 30% by weight or more. If the content of reactive functional group-containing units in polymer (C1) is within the above range, the effect of improving the melt viscosity of the polyester resin (A) by the modifier (C) can be good. As a result, even if the polyester resin (A) contains recycled polyester resin, for example, it is possible to obtain a resin composition with a melt viscosity high enough to mold a bottle with excellent strength.

[0082] The content of epoxy group-containing (meth)acrylate units in polymer (C1) is not particularly limited, but is preferably 5% by weight or more and 60% by weight or less per 100% by weight of polymer (C1). The upper limit of the content may be 55% by weight or less, 50% by weight or less, 45% by weight or less, or 40% by weight or less, and the lower limit may be 7% by weight or more, 10% by weight or more, 15% by weight or more, 20% by weight or more, 25% by weight or more, or 30% by weight or more. If the content of epoxy group-containing units in polymer (C1) is within the above range, the effect of improving the melt viscosity of the resin composition by the modifier (C) may be better. As a result, even if the polyester resin (A) contains recycled polyester resin, for example, it is possible to obtain a resin composition with a melt viscosity high enough to mold a bottle with superior strength.

[0083] (Units without reactive functional groups) In this specification, "reactive functional group-free units" are constituent units derived from monomers that do not have reactive functional groups capable of reacting with the terminal functional groups of the polyester resin (A) (hereinafter sometimes referred to as "reactive functional group-free monomers"). In this specification, when the "monomer that does not have reactive functional groups capable of reacting with the terminal functional groups of the polyester resin (A)" is "X monomer", constituent units derived from said monomer may also be referred to as "reactive functional group-free X units". In other words, reactive functional group-free units contained in the polymer (C1) of the modifier (C) cannot react with the terminal functional groups of the polyester resin (A). Furthermore, reactive functional group-free units in polymer (C1) are also constituent units derived from monomers copolymerizable with monomers containing reactive functional groups in polymer (C1).

[0084] The reactive functional group-free monomer from which the reactive functional group-free unit in polymer (C1) originates is not particularly limited. Examples of such reactive functional group-free monomers include reactive functional group-free (meth)acrylic monomers, reactive functional group-free vinyl cyanide compounds, and reactive functional group-free aromatic vinyl compounds. The reactive functional group-free monomer may be a single type of reactive functional group-free monomer, or a combination of two or more types of reactive functional group-free monomers.

[0085] Specific examples of reactive functional group-free (meth)acrylic monomers include, for example, (meth)acrylic acid and reactive functional group-free (meth)acrylates. "Reactive functional group-free (meth)acrylate" refers to "(meth)acrylate ((meth)acrylic acid ester) that does not have a reactive functional group and is substituted or unsubstituted with a functional group other than a reactive functional group." Specific examples of reactive functional group-free (meth)acrylates include, for example, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, ocryl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, and behenyl (meth)acrylate, which are alkyl (meth)acrylates having an alkyl group with 1 to 22 carbon atoms.

[0086] The number of carbon atoms in the alkyl group in the reactive functional group-free alkyl (meth)acrylate unit is not particularly limited. From the viewpoint of the polymerizability of the monomer from which the constituent unit is derived, it is preferable that the number of carbon atoms in the alkyl group in the reactive functional group-free alkyl (meth)acrylate unit is 22 or less. Furthermore, from the viewpoint of compatibility with the polyester resin (A), it is more preferable that the number of carbon atoms in the alkyl group in the reactive functional group-free alkyl (meth)acrylate unit is 12 or less, even more preferable that it is 8 or less, and particularly preferable that it is 1 to 4 or less.

[0087] Specific examples of vinyl cyanide compounds that do not contain reactive functional groups include, for example, acrylonitrile and methacrylonitrile.

[0088] Specific examples of reactive functional group-free aromatic vinyl compounds include, for example, reactive functional group-free styrene monomers and 1-vinylnaphthalene. In this specification, "reactive functional group-free styrene monomer" means "styrene that does not have a reactive functional group and is substituted or unsubstituted with a functional group other than a reactive functional group." Specific examples of reactive functional group-free styrene monomers include, for example, styrene, vinyltoluene, α-methylstyrene, 4-methylstyrene, 3-methylstyrene, 4-methoxystyrene, 4-ethylstyrene, 4-ethoxystyrene, 3,4-dimethylstyrene, 2-chlorostyrene, 3-chlorostyrene, 4-chloro-3-methylstyrene, 3-(tert-butyl)styrene, 2,4-dichlorostyrene, and 2,6-dichlorostyrene.

[0089] The reactive functional group-free units in polymer (C1) may consist of (i) only one reactive functional group-free unit derived from any one of the reactive functional group-free monomers mentioned above, or (ii) any combination of any two or more reactive functional group-free units derived from any two or more reactive functional group-free monomers mentioned above.

[0090] From the viewpoint of obtaining a polyester resin composition with improved melt viscosity (IV value) through the reaction of the polyester resin (A) and the modifier (C), the reactive functional group-free units in the polymer (C1) preferably include one or more constituent units selected from the group consisting of (i) reactive functional group-free aromatic vinyl units and reactive functional group-free (meth)acrylic units, and may consist only of one or more constituent units selected from the group; (ii) more preferably include one or more constituent units selected from the group consisting of reactive functional group-free aromatic vinyl units and reactive functional group-free (meth)acrylate units, and may consist only of one or more constituent units selected from the group; and (iii) reactive functional group-free styrene units and reactive functional group-free (meth)acrylate units It is more preferable to include one or more constituent units selected from the group consisting of units, and it may consist only of one or more constituent units selected from said group; (iv) It is even more preferable to include one or more constituent units selected from the group consisting of 4-methylstyrene units, 3-methylstyrene units, α-methylstyrene units, styrene units, methyl (meth)acrylate units, ethyl (meth)acrylate units, propyl (meth)acrylate units, and butyl (meth)acrylate units, and it may consist only of one or more constituent units selected from said group; (v) It is particularly preferable to include one or more constituent units selected from the group consisting of styrene units, methyl methacrylate units, and butyl acrylate units, and it may consist only of one or more constituent units selected from said group.

[0091] The total content of reactive functional group-free units in polymer (C1) is not particularly limited, but is preferably 40% by weight or more and 95% by weight or less per 100% by weight of polymer (C1). The upper limit of the content may be 93% by weight or less, 90% by weight or less, 85% by weight or less, 80% by weight or less, 75% by weight or less, or 70% by weight or less, and the lower limit may be 45% by weight or more, 50% by weight or more, 55% by weight or more, or 60% by weight or more. If the total content of reactive functional group-free units in polymer (C1) is within the above range, the dispersibility of the modifier (C) can be improved in the mixing process, and the effect of the modifier (C) on improving the melt viscosity of the polyester resin (A) can be improved. As a result, even if the polyester resin (A) contains recycled polyester resin, for example, it is possible to obtain a resin composition with a melt viscosity high enough to mold a bottle with excellent strength.

[0092] The total content of reactive functional group-free aromatic vinyl units and reactive functional group-free (meth)acrylic units in polymer (C1) is not particularly limited, but is preferably 40% by weight or more and 95% by weight or less per 100% by weight of polymer (C1). The upper limit of the content may be 93% by weight or less, 90% by weight or less, 85% by weight or less, 80% by weight or less, 75% by weight or less, or 70% by weight or less, and the lower limit may be 45% by weight or more, 50% by weight or more, 55% by weight or more, or 60% by weight or more. If the total content of reactive functional group-free aromatic vinyl units and reactive functional group-free (meth)acrylic units in polymer (C1) is within the above range, the dispersibility of the modifier (C) can be further improved in the mixing step, and the effect of the modifier (C) on improving the melt viscosity of the polyester resin (A) can be further improved. As a result, even if the polyester resin (A) includes recycled polyester resin, for example, it is possible to obtain a resin composition with a high melt viscosity to the extent that it is possible to mold a bottle with superior strength. Furthermore, if the upper and lower limits of the reactive functional group content (number average) per molecule of polymer (C1) are within the aforementioned preferred range, the melt viscosity of the resin composition can be suitably improved without causing gelation and without impairing the mechanical properties, heat resistance, rheological properties, etc., of the polyester resin fibers.

[0093] The number-average content of reactive functional groups in polymer (C1) is not particularly limited. It is preferable that polymer (C1) has 2 to 10 reactive functional groups per molecule on average. The upper limit of reactive functional groups in polymer (C1) may be 8 or less, 7 or less, 6 or less, or 5 or less. The lower limit of reactive functional groups in polymer (C1) may be 3 or more, 4 or more, 5 or more, 6 or more, or 7 or more. When the number-average content of reactive functional groups in polymer (C1) is within the above-mentioned range, the melt viscosity of the polyester resin (A) can be suitably improved without causing gelation and without impairing mechanical properties, heat resistance, and rheological properties. In this specification, the "number-average content of reactive functional groups" per molecule of polymer is the value obtained by the method described in the later examples.

[0094] The number-average molecular weight of polymer (C1) is not particularly limited. From the viewpoint of balancing the thermal stability and productivity of polymer (C1) and improving the melt viscosity of the polyester resin (A), the number-average molecular weight of polymer (C1) is preferably 2,000 Da or more and 10,000 Da or less. The upper limit of the number-average molecular weight of polymer (C1) is more preferably 8,000 Da or less, even more preferably 7,000 Da or less, and particularly preferably 6,000 Da or less. The lower limit of the number-average molecular weight of polymer (C1) is more preferably 3,000 Da or more, even more preferably 4,000 Da or more, even more preferably 5,000 Da or more, and particularly preferably 6,000 Da or more. In this specification, the "number-average molecular weight" of a polymer may be the number-average molecular weight measured by a known method, and the measurement method is not particularly limited.

[0095] The polymer (C1) is preferably a non-rubber polymer. A non-rubber polymer is a polymer that does not have crosslinking structures between its molecular chains. The advantage of polymer (C1) being a non-rubber polymer is that the reaction between the reactive functional groups (e.g., epoxy groups) of polymer (C1) and the terminal functional groups of the polyester resin (A) proceeds more efficiently, making it easier to improve the melt viscosity of the resin composition.

[0096] (Method for producing polymer (C1)) The polymerization method for polymer (C1) can be any known method and is not particularly limited. For example, a polymerization method selected from bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc., can be used for polymer (C1), but emulsion polymerization is preferred.

[0097] When producing polymer (C1), it is preferable to carry out polymerization in the presence of a chain transfer agent in order to control the molecular weight. It is preferable to use a chain transfer agent in the production of polymer (C1). Polymers obtained using a chain transfer agent may contain structural units derived from the chain transfer agent. In other words, it is preferable that polymer (C1) contains structural units derived from the chain transfer agent.

[0098] Examples of chain transfer agents, though not particularly limited, include primary mercaptan chain transfer agents such as n-butyl mercaptan, n-octyl mercaptan, n-hexadecyl mercaptan, n-dodecyl mercaptan, and n-tetradecyl mercaptan; secondary mercaptan chain transfer agents such as sec-butyl mercaptan and sec-dodecyl mercaptan; tertiary mercaptan chain transfer agents such as t-dodecyl mercaptan; mercaptan compounds; thioglycolic acid esters such as 2-ethylhexyl thioglycolate, ethylene glycol dithioglycolate, trimethylolpropane tris(thioglycolate), and pentaerythritol tetrakis(thioglycolate); thiophenols; tetraethyl thiuram disulfide; pentanephenylethane; acrolein; methacrolein; allyl alcohol; carbon tetrachloride; ethylene bromide; styrene oligomers such as α-methylstyrene dimer; terpinolenes; and others. The chain transfer agent may be used alone or in combination of two or more types. The amount of chain transfer agent used should be appropriately set according to the desired number average molecular weight of the polymer (C1).

[0099] The emulsifiers that can be used in emulsion polymerization are not particularly limited, but include anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. In addition, dispersants such as polyvinyl alcohol, alkyl-substituted cellulose, polyvinylpyrrolidone, and polyacrylic acid derivatives may be used as emulsifiers. The emulsifiers may be used individually or in combination of two or more.

[0100] When employing emulsion polymerization, a pyrolysis-type initiator can be used as a radical polymerization initiator. Examples of known pyrolysis-type initiators include 2,2'-azobisisobutyronitrile, hydrogen peroxide, potassium persulfate, and ammonium persulfate.

[0101] Redox-type initiators can also be used as radical polymerization initiators. The redox-type initiators are initiators that combine (a) peroxides such as organic peroxides and inorganic peroxides, and (b) optionally a reducing agent such as sodium formaldehyde sulfoxylate or glucose, optionally a transition metal salt such as iron(II) sulfate, optionally a chelating agent such as disodium ethylenediaminetetraacetate, optionally a phosphorus-containing compound such as sodium pyrophosphate, and optionally the like. Examples of organic peroxides include t-butyl peroxyisopropyl carbonate, paramenthane hydroperoxide, cumene hydroperoxide, dicumyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, and t-hexyl peroxide. Examples of inorganic peroxides include hydrogen peroxide, potassium persulfate, and ammonium persulfate. As the radical polymerization initiator, one of the radical polymerization initiators listed above can be used, or two or more radical polymerization initiators can be used in combination.

[0102] When a redox-type initiator is used, polymerization can be carried out even at low temperatures in which the peroxide does not substantially decompose thermally, allowing the polymerization temperature to be set over a wide range. For this reason, it is preferable to use a redox-type initiator. Among redox-type initiators, those using organic peroxides such as cumene hydroperoxide, dicumyl peroxide, paramenthane hydroperoxide, and t-butyl hydroperoxide as peroxides are preferred. The amount of the initiator used, and the amounts of the reducing agent, transition metal salt, and chelating agent used when a redox-type initiator is used, can be used within known ranges.

[0103] When polymer (C1) is produced by emulsion polymerization, a latex containing polymer (C1) (e.g., aqueous latex) can be obtained. Polymer (C1) can be obtained by separating polymer (C1) from the latex containing polymer (C1). The obtained polymer (C1) can be used as a modifier (C). There are no particular limitations on the method for separating polymer (C1) from latex containing polymer (C1), but examples include salting out of polymer (C1) using an acid and a metal salt, and precipitation of polymer (C1) using an organic solvent. Polymer (C1) separated from latex containing polymer (C1) may be washed and further dried. By separating polymer (C1) from latex containing polymer (C1), washing, and further drying, polymer (C1) powder (also referred to as "powder") can be obtained. Polymer (C1) powder can also be obtained by spray drying the latex containing polymer (C1). The polymer (C1) powder obtained in this way can be used as a modifier (C).

[0104] [mix(C2)] The modifier (C) may or may not contain a polymer (C2) containing a reactive functional group unit in addition to polymer (C1). The polymer component in modifier (C) may consist only of polymer (C1), may consist only of polymer (C1) and polymer (C2), or may consist of polymer (C1), polymer (C2), and other polymers.

[0105] The case in which the modifier (C) includes polymer (C1) and polymer (C2) (hereinafter also referred to as "Case A") will be described below. In Case A, it is preferable to polymerize polymer (C1) and then polymerize polymer (C2) in the presence of polymer (C1). In Case A, if polymer (C1) is obtained by emulsion polymerization, for example, it is particularly preferable to produce polymer (C2) in latex containing polymer (C1) after producing polymer (C1). When polymer (C2) is produced in latex containing polymer (C1), a composite consisting of polymer (C1) and polymer (C2) (or containing polymer (C1) and polymer (C2)) can be obtained. In the composite, polymer (C2) may cover a part of polymer (C1). Therefore, in the composite, polymer (C1) can be referred to as the core part and polymer (C2) as the shell part. The composite may have a core-shell structure, with polymer (C1) as the core and polymer (C2) as the shell. In other words, when polymer (C2) is produced (polymerized) in latex containing polymer (C1), a composite consisting of polymer (C1) and polymer (C2) can be obtained, in which polymer (C1) forms the core and polymer (C2) forms the shell, i.e., a composite having a core-shell structure. In the composite, polymer (C2) may cover the entire polymer (C1), or at least a portion of polymer (C2) may be impregnated into the interior of particulate polymer (C1).

[0106] When the modifier (C) comprises polymer (C1) and polymer (C2), and the composite composed of polymer (C1) and polymer (C2) has a core-shell structure in which polymer (C1) forms the core and polymer (C2) forms the shell, it has the advantage of improving productivity.

[0107] As long as polymer (C2) contains reactive functional group-containing units, its other components are not particularly limited. The composition of the constituent units of polymer (C2) may be the same as or different from the composition of the constituent units of polymer (C1). In other words, the composition of monomer mixture (B) may be the same as or different from the composition of monomer mixture (A).

[0108] In case A, it is preferable that polymer (C1) and polymer (C2) are not chemically bonded together. If polymer (C1) and polymer (C2) are not chemically bonded together, polymer (C1) and polymer (C2) may exist separately from each other in the resulting resin composition.

[0109] In case A, it is particularly preferable that the polymer (C2) has a configuration that allows it to more uniformly disperse the polymer (C1) in the polyester resin (A) so that the polymer (C1), which can function as a chain extender, reacts more uniformly with the polyester resin (A) when the modifier (C) and the polyester resin (A) are mixed. In other words, it has a configuration that allows it to function as a carrier.

[0110] It is particularly preferable that polymer (C2) has a configuration that can improve the granulation properties during the production of modifier (C). When polymer (C1) is polymerized alone and powdered, it may become a fine powder that is difficult to handle. In such cases, polymer (C2) having a configuration that facilitates granulation (powdering) can be polymerized together with polymer (C1), and by isolating polymers (C1) and (C2) together, a modifier (C) with excellent handling properties can be obtained.

[0111] The polymer (C2) may consist only of reactive functional group-containing units. Preferably, the polymer (C2) contains both reactive functional group-containing units and reactive functional group-free units. When the polymer (C2) contains both reactive functional group-containing units and reactive functional group-free units, the softening point of the modifier (C) (composite) is raised, making it less likely for problems such as sticking to the surface to occur. As a result, there is the advantage of improved productivity. Furthermore, when the polymer (C2) contains both reactive functional group-containing units and reactive functional group-free units, there is also the advantage that the dispersibility of the polymer (C1) is improved because the dispersibility of the modifier (C) (composite) is improved.

[0112] Specific examples of reactive functional group-containing units in polymer (C2) are the same as those described in the section on (reactive functional group-containing units) in the section on (polymer (C1)) above, so we will refer to that description and omit the explanation here. Preferred embodiments of reactive functional group-containing units in polymer (C1) are also preferred embodiments of reactive functional group-containing units in polymer (C2). Specific examples of reactive functional group-free units in polymer (C2) are the same as those described in the section on (reactive functional group-free units) in the section on (polymer (C1)) above, so we will refer to that description and omit the explanation here. Preferred embodiments of reactive functional group-free units in polymer (C1) are also preferred embodiments of reactive functional group-free units in polymer (C2).

[0113] The reactive functional group-containing units preferably include epoxy group-containing (meth)acrylate units, and more preferably include glycidyl methacrylate units. In other words, the polymer (C2) preferably includes epoxy group-containing (meth)acrylate units, and more preferably includes glycidyl methacrylate units, as reactive functional group-containing units. This configuration has the advantage of compatibility between the modifier (C) and the polyester resin (A) and dispersibility of the modifier (C) during the melt-kneading process. The reactive functional group-containing units in polymer (C2) may consist only of epoxy group-containing (meth)acrylate units, or only of glycidyl methacrylate units.

[0114] The polymer (C2) preferably contains 0.5% to 10.0% by weight of reactive functional group-containing units per 100% by weight of the polymer (C2), more preferably 1.0% to 9.0% by weight, more preferably 1.5% to 9.5% by weight, more preferably 2.0% to 8.0% by weight, more preferably 2.5% to 7.5% by weight, more preferably 3.0% to 7.0% by weight, even more preferably 4.0% to 6.5% by weight, and particularly preferably 5.0% to 6.0% by weight. This configuration has the advantage of being able to obtain a crystalline polyester resin composition with high melt viscosity.

[0115] The polymer (C2) preferably contains one or more constituent units selected from the group consisting of aromatic vinyl units and (meth)acrylic units. This configuration has the advantage that the modifier (C) has excellent compatibility with the polyester resin (A). The "aromatic vinyl units" include both constituent units derived from reactive functional group-containing aromatic vinyl compounds (e.g., 4-vinylbenzylglycidyl ether) and constituent units derived from reactive functional group-free aromatic vinyl compounds. The "(meth)acrylic units" include both constituent units derived from reactive functional group-containing (meth)acrylic monomers and constituent units derived from reactive functional group-free (meth)acrylic monomers. For specific examples of reactive functional group-containing (meth)acrylic monomers, the description in the (reactive functional group-containing units) section of the (polymer (C1)) section can be appropriately referenced. Specific examples of reactive functional group-free aromatic vinyl compounds and reactive functional group-free (meth)acrylic monomers are the same as those described in the (Reactive Functional Group-Free Units) section of the (Polymers (C1)) section above; therefore, that description is used as a reference and the explanation is omitted here.

[0116] From the viewpoint of obtaining a polyester resin composition with improved melt viscosity (IV value) by reaction of the polyester resin (A) and the modifier (C), and from the viewpoint of the modifier (C) having excellent compatibility with the polyester resin (A), the polymer (C2) more preferably contains (i) one or more constituent units selected from the group consisting of aromatic vinyl units without reactive functional groups and alkyl (meth)acrylic units, and may consist only of one or more units selected from the group, and (ii) styrene units, reactive functional group-containing (meth)acrylate units, reactive functional group-free methyl (meth)acrylate units, reactive functional group-free ethyl (meth)acrylate units, reactive functional group-free propyl (meth)acrylate units and reactive functional groups (iii) It is more preferable to include one or more constituent units selected from the group consisting of butyl (meth)acrylate units, and it may consist of only one or more selected from said group; (iv) It is more preferable to include one or more constituent units selected from the group consisting of styrene units, glycidyl (meth)acrylate units, methyl (meth)acrylate units, ethyl (meth)acrylate units, and butyl (meth)acrylate units, and it may consist of only one or more selected from said group; (iv) It is more preferable to include one or more constituent units selected from the group consisting of styrene units, glycidyl methacrylate units, methyl methacrylate units, and butyl acrylate units, and it may consist of only one or more selected from said group.

[0117] The total content of aromatic vinyl units in polymer (C2) is not particularly limited, but is preferably 10% by weight or more and 95% by weight or less per 100% by weight of polymer (C2). The upper limit of the content may be 95% by weight or less, 90% by weight or less, or 80% by weight or less, and the lower limit may be 15% by weight or more, 20% by weight or more, or 30% by weight or more. When the total content of aromatic vinyl units in polymer (C2) is within the above range, the modifier (C) has the advantage of having excellent compatibility with the polyester resin (A).

[0118] The total content of (meth)acrylic units in polymer (C2) is not particularly limited, but is preferably 10% by weight or more and 70% by weight or less per 100% by weight of polymer (C2). The upper limit of the content may be 60% by weight or less, 50% by weight or less, 40% by weight or less, or 30% by weight or less, and the lower limit may be 15% by weight or more or 20% by weight or more. When the total content of (meth)acrylic units in polymer (C2) is within the above range, the modifier (C) has the advantage of having excellent compatibility with the polyester resin (A).

[0119] The total content of aromatic vinyl units and (meth)acrylic units in polymer (C2) is not particularly limited, but is preferably 10% by weight or more and 99% by weight or less per 100% by weight of polymer (C2). The upper limit of the content may be 95% by weight or less, 90% by weight or less, 80% by weight or less, or 70% by weight or less, and the lower limit may be 15% by weight or more, 20% by weight or more, 30% by weight or more, 40% by weight or more, 50% by weight or more, 60% by weight or more, or 70% by weight or more. When the total content of aromatic vinyl units and (meth)acrylic units in polymer (C2) is within the above range, the modifier (C) has the advantage of having excellent compatibility with the polyester resin (A).

[0120] It is preferable that the number-average molecular weight of polymer (C2) is different from that of polymer (C1). More preferably, the number-average molecular weight of polymer (C2) is greater than that of polymer (C1). With this configuration, the softening point of the modifier (C) (composite) is raised, and problems such as sticking are less likely to occur. As a result, there is the advantage of improved productivity.

[0121] The number-average molecular weight of the polymer (C2) is preferably 80,000 Da or more and 300,000 Da or less, more preferably 90,000 Da or more and 200,000 Da or less, even more preferably 95,000 Da or more and 180,000 Da or less, and particularly preferably 100,000 Da or more and 150,000 Da or less. This configuration has the advantage that the modifier (C) has excellent reactivity with the polyester resin (A).

[0122] It is preferable that the number-average content of reactive functional groups in polymer (C2) differs from the number-average content of reactive functional groups in polymer (C1). It is preferable that the number-average content of reactive functional groups in polymer (C2) is greater than the number-average content of reactive functional groups in polymer (C1). With this configuration, the modifier (C) has excellent viscosity-enhancing properties, i.e., it has excellent viscosity-increasing properties. As a result, this manufacturing method has the advantage of obtaining a crystalline polyester resin composition with a higher melt viscosity (IV value).

[0123] When the polymer (C2) contains reactive functional groups, it is preferable that the polymer (C2) has an average of 2 to 35 such reactive functional groups per polymer (C2) molecule, and more preferably 15 to 35. The lower limit of the number average content of reactive functional groups in the polymer (C2) may be 5 or more, 10 or more, 20 or more, or 25 or more, and the upper limit may be 33 or less. When the number average content of reactive functional groups in the polymer (C2) is within the above range, the melt viscosity of the resin composition can be suitably improved without causing gelation and without impairing the mechanical properties, heat resistance, rheological properties, etc. of the recycled polyester resin fibers.

[0124] It is preferable that polymer (C2) is a non-rubber polymer. This configuration has the advantage that the reaction between the reactive functional groups of polymer (C2) and the terminal functional groups of the polyester resin (A) proceeds more efficiently, and the melt viscosity of the resin composition is more easily improved. In case A, it is preferable that (i) polymer (C1) is a non-rubber polymer or polymer (C2) is a non-rubber polymer, and it is more preferable that both polymer (C1) and polymer (C2) are non-rubber polymers (for example, the entire modifier (C) (composite) is a non-rubber polymer).

[0125] Polymer (C1) and polymer (C2) may differ in one or more aspects selected from the group consisting of the composition of constituent units, number-average molecular weight, and the number-average content of reactive functional groups per molecule.

[0126] In case A described above, the content ratio of polymer (C1) and polymer (C2) in the modifier (C) is not particularly limited. In case A, for example, from the viewpoint of increasing the softening point of the modifier (C) (composite) and consequently improving the productivity of the modifier (C) (composite), it is preferable that the modifier (C) contains 15% to 70% by weight of polymer (C1) and 30% to 85% by weight of polymer (C2) per 100% by weight of the modifier (C), more preferably 20% to 70% by weight of polymer (C1) and 30% to 80% by weight of polymer (C2), even more preferably 30% to 60% by weight of polymer (C1) and 40% to 70% by weight of polymer (C2), and particularly preferably 40% to 50% by weight of polymer (C1) and 50% to 60% by weight of polymer (C2). Furthermore, in case A, for example, the production costs of the modifier (C) are preferably such that the modifier (C) contains 50% to 90% by weight of polymer (C1) and 10% to 50% by weight of polymer (C2) in 100% by weight of the modifier (C), more preferably 50% to 90% by weight of polymer (C1) and 10% to 50% by weight of polymer (C2), even more preferably 70% to 90% by weight of polymer (C1) and 10% to 30% by weight of polymer (C2), and particularly preferably 80% to 90% by weight of polymer (C1) and 10% to 20% by weight of polymer (C2).

[0127] (Method for producing polymer (C2)) The polymerization method for polymer (C2) can be any known method and is not particularly limited. For example, a polymerization method selected from bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, etc., can be used for polymer (C2), but emulsion polymerization is preferred.

[0128] When producing polymer (C2), it is preferable to carry out polymerization in the presence of a chain transfer agent in order to control the molecular weight. In other words, it is preferable that polymer (C2) contains constituent units derived from the chain transfer agent.

[0129] Regarding polymer (C2), the information in the section on [polymer (C1)] may be applied as appropriate, except for the matters mentioned above.

[0130] The amount of modifier (C) used in this manufacturing method is not particularly limited, but is preferably 0.2 parts by weight or more and 10.0 parts by weight or less, more preferably 0.4 parts by weight or more and 8.0 parts by weight or less, more preferably 0.5 parts by weight or more and 6.0 parts by weight or less, even more preferably 0.6 parts by weight or more and 4.0 parts by weight or less, even more preferably 0.8 parts by weight or more and 4.0 parts by weight or less, and particularly preferably 1.0 part by weight or more and 3.0 parts by weight or less, based on 100 parts by weight of the polyester resin (A). This configuration has the advantage of being able to further improve the melt viscosity (IV value) of the resulting crystalline polyester resin composition.

[0131] [Other resins] In the mixing step, other resins may be further mixed in addition to the polyester resin (A) and the anti-adhesion agent (B), or they may not be mixed. In this specification, "other resins" refers to resins other than the polyester resin (A). Other resins are not particularly limited, but examples include polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, polyurethane, polytetrafluoroethylene, ABS resin, heat-resistant ABS resin, AS resin, heat-resistant AS resin, acrylic resin, polyacetal, polycarbonate, modified polyphenylene ether, polyamide, and cyclic polyolefin. The other resin may be a single resin or a combination of two or more resins.

[0132] In the mixing step, if other resins are further mixed in addition to the polyester resin (A) and the anti-adhesion agent (B) and an optional modifier (C), the amount of other resins used in the mixing step is not particularly limited. For example, the amount of other resins used in the mixing step may be 0 parts by weight or more and 60 parts by weight or less, based on 100 parts by weight of the total amount of polyester resin (A) and the anti-adhesion agent (B) and the optionally included modifier (C). The upper limit of the amount used may be 50 parts by weight or less, 40 parts by weight or less, 30 parts by weight or less, 20 parts by weight or less, 10 parts by weight or less, 5 parts by weight or less, or 1 part by weight or less.

[0133] [Other additives] In the mixing step, additives that can be incorporated into general thermoplastic resin compositions may be further mixed with the mixture of the polyester resin (A), the anti-sticking agent (B), an optional modifier (C), and any other resin. Such additives are not particularly limited, but examples include flame retardants, flame retardant enhancers, anti-dripping agents, reinforcing agents, fillers, antioxidants, pigments, dyes, conductivity imparters, hydrolysis inhibitors, thickeners, plasticizers, lubricants, ultraviolet absorbers, antistatic agents, flow improvers, mold release agents, compatibilizers, and heat stabilizers. The additive may be a single additive or a combination of two or more additives.

[0134] [Mixing process] This manufacturing method includes a mixing step of mixing a polyester resin (A) and an anti-adhesion agent (B). In the mixing step, at least the polyester resin (A) and the anti-adhesion agent (B) may be mixed. The mixing step may also include a raw material that contains at least the polyester resin (A) and the anti-adhesion agent (B), and optionally includes a modifier (C), other resins and / or other additives.

[0135] For mixing the raw materials containing the polyester resin (A) and the anti-adhesion agent (B), known devices such as a Henschel mixer or a tumbler mixer can be used.

[0136] [Heating process] This manufacturing method includes a heating step of heating the mixture obtained in the mixing step to 115°C or higher. The heating step may be a step of crystallizing the uncrystalline polyester resin that may be contained in the polyester resin (A) in the mixture. The heating step may also be a step of drying the resulting crystalline polyester resin composition. More specifically, the heating step corresponds to both a step of crystallizing the crystalline polyester resin contained in the polyester resin (A) and a step of drying the resulting crystalline polyester resin composition.

[0137] In the aforementioned heating step, a dried crystalline polyester resin composition suitable for various molding methods described later can be suitably produced.

[0138] As described above, according to this manufacturing method, in order to provide a crystalline polyester resin in a state in which adhesion is prevented or reduced during the heating step, it is not necessary to heat the polyester resin (A) while stirring to crystallize it. In other words, the heating step may be a step of heating the mixture without stirring. Therefore, it is not necessary to use the expensive crystallization equipment for stirring, and the heating step can be carried out using a normal heating device such as a dryer. Accordingly, according to this manufacturing method, a crystalline polyester resin can be provided at low cost, and in a state in which adhesion between polyester resins is prevented or reduced.

[0139] If the heating step is a step in which the mixture is heated without stirring, the heating step may also be a step in which the mixture is left (set to rest) in an ambient temperature (temperature environment) of 115°C or higher, for example, in a dryer set to 115°C or higher.

[0140] The heating temperature in the heating step is 115°C or higher. A higher heating temperature allows for more favorable crystallization of the polyester resin (A) and drying of the crystallized polyester resin composition during the heating step. From this viewpoint, the heating temperature is preferably 120°C or higher, more preferably 125°C or higher, and even more preferably 130°C or higher. On the other hand, if the heating temperature is excessively high, the polyester resin (A) and the anti-adhesion agent may undergo thermal decomposition. Furthermore, if the heating temperature is excessively high, more energy than necessary is consumed, which also presents cost problems. From the viewpoint of avoiding these issues, the heating temperature is preferably 150°C or lower, more preferably 145°C or lower, and even more preferably 135°C or lower. Note that the heating temperature, when a dryer is used in the heating step, refers to the set temperature of the dryer, specifically the ambient temperature inside the dryer.

[0141] By ensuring that the heating time in the heating step is longer than a predetermined time, the crystallization of the amorphous polyester resin and the drying of the crystallized polyester resin composition proceed sufficiently during the heating step. The heating time can be appropriately determined based on the amount of the mixture subjected to the heating step and the heating temperature, and is not particularly limited. The specific lower limit of the heating time may be, for example, 2 hours or more, preferably 2.5 hours or more, and more preferably 3 hours or more. Furthermore, the specific upper limit of the heating time is, for example, preferably 5 hours or less, and more preferably 4 hours or less, from the viewpoint of preventing increased costs due to heating for an unnecessarily long time.

[0142] [Liquid substance application process] The present manufacturing method may further include a liquid substance application step, in which a liquid substance is applied to at least a portion of the surface of the polyester resin (A) before the mixing step. As described above, by further including the liquid substance application step, the polyester resin (A) and the anti-adhesion agent (B) adhere more firmly via the liquid substance during the mixing step of the present manufacturing method. As a result, according to the present manufacturing method, the surface of the polyester resin (A) is more preferably coated with the anti-adhesion agent (B) during the mixing step, and the adhesion is more preferably prevented or reduced.

[0143] In the liquid substance attachment step, known methods can be used to attach the liquid substance to at least a portion of the surface of the polyester resin (A), and are not particularly limited. For example, a method of mixing the polyester resin (A) and the liquid substance can be used. Known equipment can be used when mixing the polyester resin (A) and the liquid substance. For example, the mixer mentioned above can be used as the equipment used in the mixing step.

[0144] Here, the statement that the liquid substance attachment step involves attaching a liquid substance to at least a portion of the surface of the polyester resin (A) before the mixing step means that the polyester resin (A) with the liquid substance obtained in the liquid substance attachment step attached to at least a portion of its surface is subjected to the mixing step. In that case, in the mixing step, the polyester resin (A) with the liquid substance attached to at least a portion of its surface is mixed with an anti-adhesion agent (B), and optionally a modifier (C), other resins and other additives and other raw materials.

[0145] The crystalline polyester resin composition obtained through this manufacturing method can be suitably used in blow molding, particularly injection blow molding, as described later. The crystalline polyester resin composition obtained through this manufacturing method can be subjected to various molding methods other than blow molding (e.g., injection molding, extrusion molding, calendering, inflation molding, rotational molding, and press molding) to obtain various molded articles.

[0146] The crystalline polyester resin composition obtained by this manufacturing method is typically in the form of pellets.

[0147] [3. Method for manufacturing molded articles] A method for manufacturing a molded article according to one embodiment of the present invention includes a molding step of molding a crystalline polyester resin composition obtained through the manufacturing method described in section 2. Method for manufacturing a crystalline polyester resin composition. A molded article obtained by the method for manufacturing a molded article according to one embodiment of the present invention is also one embodiment of the present invention. A molded article obtained by the method for manufacturing a molded article according to one embodiment of the present invention can also be called a polyester resin molded article.

[0148] In the method for manufacturing a molded article according to one embodiment of the present invention, the method for molding the crystalline polyester resin composition in the molding step can be a known molding method and is not particularly limited. The molding method may be, for example, extrusion molding, injection molding, or blow molding. In other words, the molding step may be a step of molding the crystalline polyester resin composition by extrusion molding, injection molding, or blow molding. Furthermore, the blow molding may be, for example, direct blow molding or injection blow molding.

[0149] In one embodiment of the present invention, direct blow molding is a method of producing a molded body which is a blow-molded body by extruding the crystallized polyester resin composition to obtain a tubular parison and blowing a gas such as air into the parison. In another embodiment of the present invention, injection blow molding is a method of producing a molded body which is a blow-molded body by injection molding the crystallized polyester resin composition to obtain a preform which is an injection-molded body and blowing a gas such as air into the preform.

[0150] In the method for manufacturing a molded article according to one embodiment of the present invention, the specific method for molding the crystallized polyester resin composition is not particularly limited, and known methods can be applied. For example, if extrusion molding is adopted as the molding method, a known extrusion molding method can be adopted. For example, if injection molding is adopted as the molding method, a known injection molding method can be adopted. For example, if blow molding is adopted as the molding method, a known blow molding method can be adopted.

[0151] [4.Applications] According to one embodiment of the present invention, a method for producing a crystallized polyester resin composition can be provided. According to the method for producing a crystallized polyester resin composition according to one embodiment of the present invention, a crystallized polyester resin composition suitable for molding can be provided at low cost, as adhesion between polyester resins is prevented or reduced. By using the crystallized polyester resin composition obtained through the method for producing a crystallized polyester resin composition according to one embodiment of the present invention, blow molding (particularly injection blow molding) can be easily performed. Therefore, one embodiment of the present invention is not particularly limited, but can be suitably used in automotive applications such as cylinder head covers, engine covers, intake manifolds, radiator tanks, oil pans, accelerator pedals, canisters, fuel tubes, air brake tubes, exhaust gas tubes, hydrogen injectors, ducts, industrial fasteners, and door mirror stays; electrical and electronic applications such as coil bobbins, connectors, gears, sockets, switches, electric blanket coated wires, fiber optic cable coatings, power tools, and wire binding materials; mechanical applications such as hydraulic and pneumatic connectors and tubes, bearings, covers and housings, bearings, pressure-resistant hoses, and cable ties; building materials applications such as curtain rail components, aluminum sash corners, door rollers, handrails, curtain rollers, and door handles; sports and leisure applications such as sports shoe soles, ski and snowboard equipment, reels, and diving snorkels; packaging materials and container applications such as shrink wrap film, food packaging film, alcoholic beverage bottles, beverage bottles, and pesticide bottles; and medical applications such as toothbrushes, chair legs and armrests, and sutures.

[0152] One embodiment of the present invention may have the following configuration. [1] A mixing step of mixing polyester resin (A) and anti-adhesion agent (B), A method for producing a crystalline polyester resin composition, comprising a heating step of heating the mixture obtained in the mixing step to 115°C or higher. [2] The method for producing a crystalline polyester resin composition according to [1], wherein the heating step is a step of heating the mixture without stirring. [3] The method for producing the crystalline polyester resin composition according to [1] or [2], wherein the anti-adhesion agent (B) is an inorganic substance. [4] The method for producing the crystalline polyester resin composition according to [3], wherein the inorganic substance is one or more selected from the group consisting of talc, light calcium carbonate, heavy calcium carbonate, mica, clay, silica, hydrotalcite, aluminum hydroxide, magnesium hydroxide, antimony oxide, titanium oxide, and glass powder. [5] A method for producing a crystallized polyester resin composition according to any one of [1] to [4], further comprising a liquid substance attachment step of attaching a liquid substance to at least a portion of the surface of the polyester resin (A) before the mixing step. [6] The method for producing a crystalline polyester resin composition according to [5], wherein the liquid is one or more selected from the group consisting of liquid paraffin, process oil, epoxidized vegetable oil, acrylic oligomer, and plasticizer. [7] A method for producing a crystalline polyester resin composition according to any one of [1] to [6], wherein the polyester resin (A) includes an amorphous polyester resin. [8] The method for producing the crystallized polyester resin composition according to [7], wherein the content of the amorphous polyester resin in the polyester resin (A) is 5% by weight or more and 60% by weight or less based on 100% by weight of the total weight of the polyester resin (A). [9] A method for producing the crystalline polyester resin composition according to [7] or [8], wherein the amorphous polyester resin contains glycol-modified polyethylene terephthalate.

[10] The mixing step is a step of mixing the resin composition containing the polyester resin (A) and the modifier (C) with the anti-adhesion agent (B), A method for producing a crystalline polyester resin composition according to any one of [1] to [9], wherein the modifier (C) comprises a polymer (C1) containing a reactive functional group-containing unit and a reactive functional group-free unit.

[11] The modifier (C) further comprises a polymer (C2) containing a reactive functional group-containing unit, A method for producing a crystalline polyester resin composition according to

[10] , wherein the content of the polymer (C1) and the polymer (C2) in the modifier (C) is 50% by weight or more and 90% by weight or less of the polymer (C1) and 10% by weight or more and 50% by weight or less of the polymer (C2) in 100% of the modifier (C).

[12] The method for producing a crystalline polyester resin composition according to

[11] , wherein the content of the reactive functional group-containing unit in the polymer (C2) is 0.5% by weight or more and 10.0% by weight or less in 100% by weight of the polymer (C2).

[13] A method for producing a crystalline polyester resin composition according to

[11] or

[12] , wherein the reactive functional group-containing unit in the polymer (C2) includes an epoxy group-containing (meth)acrylate unit.

[14] A method for producing a crystalline polyester resin composition according to any one of

[11] to

[13] , wherein the polymer (C2) further comprises aromatic vinyl units and / or (meth)acrylic units as constituent units.

[15] The polymer (C1) is (i) The reactive functional group-containing unit includes an epoxy group-containing (meth)acrylate unit, (ii) A method for producing a crystalline polyester resin composition according to any one of

[10] to

[14] , wherein the reactive functional group-free unit comprises one or more constituent units selected from the group consisting of reactive functional group-free aromatic vinyl units and reactive functional group-free (meth)acrylate units.

[16] The method for producing the crystallized polyester resin composition according to any one of

[10] to

[15] , wherein the amount of the modifier (C) used in the method for producing the crystallized polyester resin composition is 0.2 parts by weight or more and 10.0 parts by weight or less per 100 parts by weight of the polyester resin (A) used.

[17] A method for producing a crystallized polyester resin composition according to any one of [1] to

[16] , wherein the polyester resin (A) includes a recycled polyester resin.

[18] A method for producing a crystalline polyester resin composition according to any one of [1] to

[17] , wherein the polyester resin (A) comprises one or more selected from the group consisting of polyethylene terephthalate and polybutylene terephthalate. A method for producing a molded article, comprising a molding step of molding a crystalline polyester resin composition obtained by a method for producing a crystalline polyester resin composition described in any one of [1] to

[18] .

[20] The method for manufacturing a molded article according to

[19] , wherein the molding step is a step of molding the crystallized polyester resin composition by extrusion molding, injection molding or blow molding.

[21] The method for manufacturing a molded article according to

[20] , wherein the blow molding is direct blow molding or injection blow molding. [Examples]

[0153] The present invention will be described more specifically with reference to the following examples and comparative examples, but the present invention is not limited to these, and examples obtained by appropriately combining the technical means disclosed in each example are also included within the scope of the present invention.

[0154] [Measurement methods and evaluation methods] <Blocking properties> The blocking properties of the crystalline polyester resin compositions produced on a 1 kg stainless steel tray in the examples and comparative examples were visually evaluated according to the following criteria. A rating of "Good" or "Acceptable" indicates that no blocking occurred, the adhesion of crystalline polyester resins was prevented or reduced, and the crystalline polyester resin composition did not form clumps. A rating of "Unacceptable" indicates that blocking occurred, the adhesion of crystalline polyester resins could not be prevented or reduced, and the crystalline polyester resin composition formed clumps. • Evaluation criteria "Good": No pellets are stuck together. "OK": It is stuck, but it will come loose if you shake the bat. "Impossible": It is stuck and will not move or come loose even when the bat is shaken.

[0155] [Raw materials] The substances used in the examples and comparative examples are shown below.

[0156] <Polyester resin (A)> A1: Virgin polyester resin (Teijin PET resin MTJ) A2: Recycled polyester resin obtained by recycling PET bottles.

[0157] <Anti-sticking agent (B)> • B1: Talc (PAAB, manufactured by Nippon Talc Co., Ltd.) • B2: Calcium carbonate (manufactured by Shiraishi Calcium Co., Ltd., CC-R) <Liquid> • Liquid paraffin <Modifier (C)> • Modifier (C): The modifier obtained in the following manufacturing example 1 was used.

[0158] <Manufacturing Example 1: Preparation of Modifier> (Preparation of polymer (C1)) First, purified water (180 parts by weight), sodium formaldehyde sulfoxylate (1.5 parts by weight), ethylenediaminetetraacetic acid (EDTA) (0.0075 parts by weight), ferrous sulfate heptahydrate (0.3 parts by weight), and t-butyl hydroperoxide (0.1 parts by weight) were added to the reactor.

[0159] Subsequently, the temperature inside the reactor was raised to 75°C while stirring the raw materials, and nitrogen was bubbled into the raw materials inside the reactor for 30 minutes.

[0160] Next, a monomer mixture consisting of styrene (ST) (70 parts by weight), a monomer without reactive functional groups, glycidyl methacrylate (GMA) (10 parts by weight), a monomer containing reactive functional groups, and n-octyl mercaptan (1.5 parts by weight), a chain transfer agent, was added to the reactor over 150 minutes. Furthermore, t-butyl hydroperoxide (0.1 parts by weight) was added to the reactor sequentially at the same time as the addition of the monomer mixture. The mixture in the reactor was then reacted until the polymerization conversion rate reached 90% or more. After the polymerization conversion rate reached 90%, the mixture in the reactor was reacted for a further 30 minutes. Polymer (C1) was obtained by this operation.

[0161] (Preparation of polymer (C2) and modifier) Next, a monomer mixture consisting of butyl acrylate (5 parts by weight), GMA (1 part by weight), and ST (14 parts by weight) was added to the reactor containing the polymer (C1). During the addition of the monomer mixture, sodium ethoxyalkylated alkyl phosphate (0.2 parts by weight) and t-butyl hydroperoxide (0.03 parts by weight) were added to the reactor as needed.

[0162] Next, the mixture in the reactor was reacted until the polymerization conversion rate reached 98% or higher to obtain polymer (C2). As a result, a latex containing a modifier, which was a composite of polymer (C1) and polymer (C2), was obtained. Polymer (C2) contained 5% by weight of GMA units as reactive functional group-containing units per 100% by weight of polymer (C2).

[0163] Using the method described above, the volume-average particle size of the modifier in the latex was measured to be 1100 angstroms. Furthermore, it can be considered that polymer (C1) forms the core portion and polymer (C2) forms the shell portion in the modifier. In other words, the modifier can be considered to have a core-shell structure. The modifier contained 80% by weight of polymer (C1) and 20% by weight of polymer (C2) per 100% by weight of the modifier. The number-average molecular weight of the modifier was measured using the method described above. As a result, the modifier had two different number-average molecular weights (Mn): the number-average molecular weight of polymer (C1) was 7,000 Da, and the number-average molecular weight of polymer (C2) was 12,000 Da. As measured using the method described above, the average number of reactive functional groups (epoxy groups) per molecule of polymer (C1) was 9.

[0164] To recover the modifier as a powder from the latex, the latex was quickly added to a 5% calcium chloride aqueous solution while stirring the solution. The resulting mixture was heated to 70°C using steam heating and maintained at that temperature. Next, the temperature of the mixture was raised to 85°C to form aggregates of the modifier in the mixture, and then the mixture was dehydrated to obtain the aggregates of the modifier. The obtained aggregates of the modifier were dried to obtain modifier powder. Subsequently, the modifier powder was sieved through an 18-mesh screen to obtain the white powder that passed through the 18-mesh screen. The obtained white powder was used as "modifier (C)".

[0165] [Example 1] (Liquid substance application process) 100 parts by weight of A1 as a polyester resin (A) and 0.0010 parts by weight of liquid paraffin as a liquid substance were added to a mixer (manufacturer: Kawata Co., Ltd., product name: Super Mixer), and the two were mixed. As a result, a polyester resin (A) was obtained that was in pellet form and had the liquid paraffin attached to at least a portion of its surface.

[0166] (Mixing process) Next, 0.50 parts by weight of B1 as an anti-adhesion agent (B) was added to the mixer, and the two were mixed to obtain a mixture 1 of polyester resin (A) with the liquid substance adhering to at least a portion of its surface and anti-adhesion agent (B).

[0167] (Heating process) The obtained mixture 1 was placed on a 1 kg stainless steel tray. The tray containing mixture 1 was placed in a box-type dryer (manufacturer: ESPEC Corporation, product name: PV-331), and the temperature inside the box-type dryer was set to 130°C, and mixture 1 was heated for 3 hours. As a result, the polyester resin (A) in mixture 1 crystallized, and a crystalline polyester resin composition was produced. The produced crystalline polyester resin composition is referred to as crystalline polyester resin composition 1.

[0168] [Example 2] The same procedure as in Example 1 was followed, except that the amount of anti-adhesion agent (B), B1, was changed to 0.25 parts by weight. As a result, a crystalline polyester resin composition was produced. The produced crystalline polyester resin composition will be referred to as crystalline polyester resin composition 2.

[0169] [Example 3] The same procedure as in Example 1 was followed, except that the amount of anti-adhesion agent (B), B1, was changed to 0.10 parts by weight. As a result, a crystalline polyester resin composition was produced. The produced crystalline polyester resin composition will be referred to as crystalline polyester resin composition 3.

[0170] [Example 4] The same procedure as in Example 1 was followed, except that the amount of anti-adhesion agent (B), B1, was changed to 0.05 parts by weight. As a result, a crystalline polyester resin composition was produced. The produced crystalline polyester resin composition is referred to as crystalline polyester resin composition 4.

[0171] [Example 5] The same procedure as in Example 1 was followed, except that B2 was used instead of B1 as the anti-adhesion agent (B). As a result, a crystalline polyester resin composition was produced. The produced crystalline polyester resin composition is referred to as crystalline polyester resin composition 5.

[0172] [Example 6] The same procedure as in Example 1 was followed, except that B2 was used instead of B1 as the anti-adhesion agent (B), and the amount used was changed to 0.25 parts by weight. As a result, a crystalline polyester resin composition was produced. The produced crystalline polyester resin composition is referred to as crystalline polyester resin composition 6.

[0173] [Example 7] The same procedure as in Example 1 was followed, except that B2 was used instead of B1 as the anti-adhesion agent (B), and the amount used was changed to 0.10 parts by weight. As a result, a crystalline polyester resin composition was produced. The produced crystalline polyester resin composition is referred to as crystalline polyester resin composition 7.

[0174] [Example 8] The same procedure as in Example 1 was followed, except that B2 was used instead of B1 as the anti-adhesion agent (B), and the amount used was changed to 0.05 parts by weight. As a result, a crystalline polyester resin composition was produced. The produced crystalline polyester resin composition is referred to as crystalline polyester resin composition 8.

[0175] [Comparative Example 1] The same procedure as in Example 1 was followed, except that the anti-adhesion agent (B) and liquid substances were not used. Specifically, 100 parts by weight of A1 as the polyester resin (A) was heated using the same heating method as in Example 1. As a result, a crystallized polyester resin composition was produced. The produced crystallized polyester resin composition will be referred to as comparative crystallized polyester resin composition 1.

[0176] [Comparative Example 2] The same procedure as in Example 1 was followed, except that the anti-adhesion agent (B) was not used. Specifically, a polyester resin (A) in pellet form with the liquid substance attached to at least a portion of its surface was obtained using the same method as in Example 1. Subsequently, the polyester resin (A) with the liquid substance, liquid paraffin, attached to at least a portion of its surface was heated using the same heating method as in Example 1. As a result, a crystallized polyester resin composition was produced. The produced crystallized polyester resin composition is referred to as comparative crystallized polyester resin composition 2.

[0177] [Examples 9 to 16, Comparative Examples 3 and 4] 99 parts by weight of polyester resin (A) A2 and 1 part by weight of modifier (C) were mixed in a tumbler mixer to obtain a mixture. The obtained mixture was subjected to a 25 mm twin-screw extruder and melt-kneaded under the following conditions to obtain a resin composition. The obtained resin composition was alloyed and in pellet form. Hereinafter, the obtained pellet-shaped resin composition will be referred to as pellet A. Extrusion conditions: Temperature; C1 / C2 / C3 / C4 / C5 / C6 / C7 / D = 100℃ / 245℃ / 245℃ / 245℃ / 245℃ / 245℃ / 250℃ / 250℃ (C stands for cylinder, D stands for die) Screw rotation speed: 250 rpm, Discharge amount: 15kg / hour.

[0178] Examples 9 to 16, and Comparative Examples 3 and 4, were constructed by performing the same procedures as in Examples 1 to 8 and Comparative Examples 1 and 2, respectively, except that the obtained pellet A was used instead of A1.

[0179] The crystalline polyester resin compositions produced in Examples 9 to 16, and Comparative Examples 3 and 4, are referred to as crystalline polyester resin compositions 9 to 16, and comparative crystalline polyester resin compositions 3 and 4, respectively.

[0180] [Examples 17 to 27] Examples 17 to 27 were constructed by performing the same procedures as in Examples 1 to 5, 8, 9, 11 to 13, and 16, except that the amount of liquid paraffin used was changed from 0.0010 parts by weight to 0.0200 parts by weight.

[0181] The crystalline polyester resin compositions produced in Examples 17 to 27 are referred to as crystalline polyester resin compositions 17 to 27, respectively.

[0182] [result] The types and amounts of polyester resin (A), liquid, anti-adhesion agent (B), and modifier (C) used in Examples 1 to 27 and Comparative Examples 1 to 4, as well as the results of evaluating the presence or absence of blocking of the crystallized polyester resin compositions using the method described above, are shown in Tables 1 and 2 below.

[0183] [Table 1]

[0184] [Table 2]

[0185] Based on the descriptions in Table 1 and Examples 1 to 27, the methods for producing the crystalline polyester resin compositions in Examples 1 to 27 satisfy the following requirements (1) and (2). (1) The process includes a mixing step of mixing a polyester resin (A) and an anti-adhesion agent (B). (2) A heating step of heating the mixture obtained in the mixing step to 115°C or higher. Therefore, the methods for producing crystalline polyester resin compositions in Examples 1 to 27 correspond to the present production method.

[0186] On the other hand, as shown in Table 2, Comparative Examples 1 to 4 do not use the anti-adhesion agent (B), and therefore do not have the mixing step described above, and thus do not fall under the present manufacturing method.

[0187] Furthermore, as shown in Table 2, in comparative crystalline polyester resin compositions 1 to 4 obtained in Comparative Examples 1 to 4, blocking occurred, and the adhesion between crystalline polyester resins could not be prevented or reduced. On the other hand, as shown in Table 1, in crystalline polyester resin compositions 1 to 27 obtained in Examples 1 to 27, no blocking occurred, indicating that the adhesion between crystalline polyester resins was prevented or reduced. In addition, the box-type dryers used in Examples 1 to 16 are inexpensive dryers, unlike expensive crystallization equipment.

[0188] From the above, it was found that this manufacturing method can solve the problem of providing crystalline polyester resins at low cost and in a state where adhesion between polyester resins is prevented or reduced.

[0189] Furthermore, the results from Examples 9 to 16 and 23 to 27 show that this manufacturing method can solve the aforementioned problems even when recycled polyester resin is used as a raw material, and / or when modifier (C) is used. [Industrial applicability]

[0190] According to a method for producing a crystallized polyester resin composition according to one embodiment of the present invention, a crystallized polyester resin composition that is suitable for molding can be provided at low cost because adhesion between polyester resins is prevented or reduced. Therefore, one embodiment of the present invention can be suitably used in the manufacture of molded products such as: automotive applications such as cylinder head covers, engine covers, intake manifolds, radiator tanks, oil pans, accelerator pedals, canisters, fuel tubes, air brake tubes, exhaust gas tubes, hydrogen injectors, ducts, industrial fasteners, and door mirror stays; electrical and electronic applications such as coil bobbins, connectors, gears, sockets, switches, electric blanket coated wires, fiber optic cable coatings, power tools, and wire binding materials; mechanical applications such as hydraulic and pneumatic connectors and tubes, bearings, covers and housings, bearings, pressure-resistant hoses, and cable ties; building materials applications such as curtain rail components, aluminum sash corners, door rollers, handrails, curtain rollers, and door handles; sports and leisure applications such as sports shoe soles, ski and snowboard equipment, reels, and diving snorkels; packaging materials and container applications such as shrink wrapping film, food packaging film, alcoholic beverage bottles, beverage bottles, and pesticide bottles; and medical applications such as toothbrushes, chair legs and armrests, and sutures.

Claims

1. A mixing step of mixing a polyester resin (A) and an anti-adhesion agent (B), A method for producing a crystalline polyester resin composition, comprising a heating step of heating the mixture obtained in the mixing step to 115°C or higher.

2. The method for producing a crystalline polyester resin composition according to claim 1, wherein the heating step is a step of heating the mixture without stirring.

3. The method for producing a crystalline polyester resin composition according to claim 1, wherein the anti-adhesion agent (B) is an inorganic substance.

4. The method for producing a crystalline polyester resin composition according to claim 3, wherein the inorganic substance is one or more selected from the group consisting of talc, light calcium carbonate, heavy calcium carbonate, mica, clay, silica, hydrotalcite, aluminum hydroxide, magnesium hydroxide, antimony oxide, titanium oxide, and glass powder.

5. A method for producing a crystallized polyester resin composition according to claim 1, further comprising a liquid substance attachment step of attaching a liquid substance to at least a portion of the surface of the polyester resin (A) before the mixing step.

6. The method for producing a crystalline polyester resin composition according to claim 5, wherein the liquid is one or more selected from the group consisting of liquid paraffin, process oil, epoxidized vegetable oil, acrylic oligomer, and plasticizer.

7. The method for producing a crystalline polyester resin composition according to claim 1, wherein the polyester resin (A) includes an amorphous polyester resin.

8. The method for producing a crystallized polyester resin composition according to claim 7, wherein the content of the amorphous polyester resin in the polyester resin (A) is 5% by weight or more and 60% by weight or less based on 100% by weight of the total weight of the polyester resin (A).

9. The method for producing the crystalline polyester resin composition according to claim 7, wherein the amorphous polyester resin includes glycol-modified polyethylene terephthalate.

10. The mixing step is a step of mixing the resin composition containing the polyester resin (A) and the modifier (C) with the anti-adhesion agent (B), The method for producing a crystalline polyester resin composition according to claim 1, wherein the modifier (C) comprises a polymer (C1) containing a reactive functional group-containing unit and a reactive functional group-free unit.

11. The modifier (C) further comprises a polymer (C2) containing a reactive functional group-containing unit, A method for producing a crystalline polyester resin composition according to claim 10, wherein the content of polymer (C1) and polymer (C2) in the modifier (C) is 50% by weight or more and 90% by weight or less of polymer (C1) and 10% by weight or more and 50% by weight or less of polymer (C2) in 100% of the modifier (C).

12. A method for producing a crystalline polyester resin composition according to claim 11, wherein the content of the reactive functional group-containing unit in the polymer (C2) is 0.5% by weight or more and 10.0% by weight or less based on 100% by weight of the polymer (C2).

13. A method for producing a crystalline polyester resin composition according to claim 11, wherein the reactive functional group-containing unit in the polymer (C2) includes an epoxy group-containing (meth)acrylate unit.

14. The method for producing a crystalline polyester resin composition according to claim 11, wherein the polymer (C2) further comprises aromatic vinyl units and / or (meth)acrylic units as constituent units.

15. The polymer (C1) is (i) The reactive functional group-containing unit includes an epoxy group-containing (meth)acrylate unit, (ii) The method for producing a crystalline polyester resin composition according to claim 10, wherein the reactive functional group-free unit comprises one or more constituent units selected from the group consisting of reactive functional group-free aromatic vinyl units and reactive functional group-free (meth)acrylate units.

16. The method for producing the crystallized polyester resin composition according to claim 10, wherein the amount of the modifier (C) used in the method for producing the crystallized polyester resin composition is 0.2 parts by weight or more and 10.0 parts by weight or less per 100 parts by weight of the polyester resin (A) used.

17. The method for producing the crystallized polyester resin composition according to claim 1, wherein the polyester resin (A) includes a recycled polyester resin.

18. The method for producing a crystalline polyester resin composition according to claim 1, wherein the polyester resin (A) comprises one or more selected from the group consisting of polyethylene terephthalate and polybutylene terephthalate.

19. A method for producing a molded article, comprising a molding step of molding a crystalline polyester resin composition obtained by a method for producing a crystalline polyester resin composition according to any one of claims 1 to 18.

20. The method for manufacturing a molded article according to claim 19, wherein the molding step is a step of molding the crystallized polyester resin composition by extrusion molding, injection molding or blow molding.

21. The method for manufacturing a molded article according to claim 20, wherein the blow molding is direct blow molding or injection blow molding.

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